Managing migraine in pregnancy

A 36 year old woman who is 17 weeks pregnant with a 15 year history of migraine presents with an episode of a frontal unilateral headache. It is associated with nausea and visual aura consisting of mainly zigzag lines. She says that this headache is similar to her usual migraines, with two other episodes during this pregnancy so far, each lasting for about five or six hours and then resolving. Clinical examination is normal, including blood pressure and urine analysis.

Migraine is one of the commonest neurological complaints in pregnancy, and most affected women either self manage or are managed by non-specialists.1 Many women with a pre-existing history of migraine attacks will see an improvement during pregnancy (particularly those with menstrual related migraine), while those who have migraine with aura are more likely to have an unpredictable course. For a few women, migraine may occur for the first time during pregnancy, which causes anxiety and poses a diagnostic challenge.1 The urgent priority when a patient presents with a headache during pregnancy should be to distinguish primary causes (such as migraine, tension headaches, and cluster headaches) from serious secondary causes. Secondary causes of headaches (such as pre-eclampsia and cerebral venous thrombosis) require urgent assessment and are more likely to occur after 12 weeks gestation (box 1).2